This invention relates to a fluid filled insole.
An insole worn in a shoe can be a source of comfort to the wearer. The common form, fashioned of foam material provides a surface for the foot to push against that is more resilient than the normal inner surface of a shoe sole. In addition, the insole is a replaceable element which covers wrinkles that might form in the inner surface of the shoe sole.
A fluid filled insole is capable of providing even more comfortable wear because of the particular distribution of support produced by a fluid. In addition, the structure of the insole can permit the fluid to flow back and forth in a controlled fashion during walking so as to produce a massaging action on the foot.
Unfortunately, existing fluid filled insoles have several shortcomings. The insoles are usually made of vinyl; as a result, the feet of the wearer have a tendency to get hot from the insoles. In addition, the flow of the fluid during walking is not optimal. There are barriers in the insole which prevent the flow of fluid in certain directions, but in spaces between the barriers, the fluid moves somewhat too swiftly to uncompressed regions of the insole. There is also a durability problem with these insoles caused by the wrinkling and shearing forces to which they are subjected.
In accordance with the present invention, it has been determined that the use of openings or apertures in the insole provides a ventilating effect as the wearer walks, compressing different parts of the insole. This ventilation keeps the foot from getting hot. In addition, the placement of the apertures provides improved flow patterns, including a slower, turbulent flow, evenly distributed around the apertures.